My period was july 9, 2013 - july 15, 2013 I have a 28 day cycle if I have sex before july 27, 2013 can I be pregnant .

In brief:
Yes

Follicular phase is the time from the start of menses to ovulation; luteal phase is the time from ovulation to menses. The luteal phase is the most consistent, averages 14 days, but can be 12-16 days. Follicular phase can vary considerably.
In your example, ovulation would occur before 7/27.

In brief:
Yes

Follicular phase is the time from the start of menses to ovulation; luteal phase is the time from ovulation to menses. The luteal phase is the most consistent, averages 14 days, but can be 12-16 days. Follicular phase can vary considerably.
In your example, ovulation would occur before 7/27.
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